The present invention relates to a controller for an inverter circuit. The invention also relates to an inverter with an inverter circuit. The invention further relates to a method for operating an inverter.
Voltage-controlled inverters without voltage sensors on the AC side of the inverter are known in the art. Current control is hereby carried out by using fictitious direct current values in a Cartesian d-q-co-ordinate system of the rotor of a fictitious direct current motor, which in the control schematic represents an AC side circuit of the inverter. Eliminating voltage sensors on the AC side has cost advantages, but also the disadvantage that excessively high currents (overload currents) occur during the start-up of an inverter with small inductances, which may exceed the load limits of components, due to the fact that during start-up with small inductances, the starting currents can rise so rapidly that they are not correctly or not sufficiently accurately measured.
It would therefore be desirable and advantageous to obviate prior art shortcomings and to provide an improved controller for an inverter circuit and to provide an inverter, with which, respectively, the occurrence of excessively high currents during start-up of the inverter circuit can be avoided, even when only small inductances are used on the AC side of the inverter. It would also be desirable to provide a method for operating an inverter having these advantageous features.